1. Field of the Invention
The present invention relates to a flexible printed circuit board with shield patterns for use in cameras.
2. Related Background Art
Of the conventional flexible printed boards for use in cameras, there has been proposed a construction in which an exposed conductor is folded back itself, thereby effecting an electrical isolation.
In case of the electrical control of the operation of a camera, in order to prevent erroneous operations of a camera due to external electrical noise, there has been proposed to plate the back surface of a component having plastic outer surfaces with a metal or to attach a special designed shield sheet to the back surface thereof. However, the above-described techniques have the following problems.
First, in the case of the construction in which the folded back portions are provided to attain electrical isolation, there has been no idea to prevent the erroneous operations of a camera from external electronical noise.
When the back surface of a component having a plastic outer surfaces is plated with a metal in order to prevent erroneous operations of a camera due to external electrical noise, the cost of the component is increased and the further increase in cost results when means for electrically isolate the metal plated surface from other electronic components is employed.
Furthermore, when a specially-designed shield sheet is used, the cost of each component is also increased and means for grounding is further required. As a result, the components are increased in cost and the number of assembly steps is increased.
Moreover, the electric circuits for cameras have been increased in size in the recent years so that the space in which the components which must be electrically shielded are installed must be secured and then the requirement for efficient arrangement of these components is increased.